Legend of Galactic Heroes by Yoshiki Tanaka, ran from 1988 to 2000, will always be one of my favourite SF series, so Tytania, written by the same author just automatically becomes one of my must watch anime series.
Dealing with issues such as wars, battles, military strategies and politics, this series is anything but light (although some classified it as a light novel series). But all of this is laid out in the most interesting ways, with characters that you can feel for and humourous scenes sprinkled throughout the show.
Take a look at OP to see what a "Space Opera" is like:
Tytania, named after the fairy queen (one of the few things that could be learned from Earl and Fairy!), alone gives hints about the clan's pride in their power over others. Although these people are knighted, they are not awarded with land or planetary systems, they don't need it, after all, as the symbol of fear, they owned everyone and everything in the galaxy.
The struggles between the clan and the opposing force forms the trunk of the story, while the dynamics between people and nations are the branches and leaves, and these paint the space opera a very lush green.
One of the nice things about having the series animated is that you can see the formations during the war. When I was reading Legend of Galactic Heroes, I had a lot of problems imagining what the battle scene would be like (lack of imagination on my part) and with the names of vessels spelt out in a long string of katakana, there were times, especially in the first few books, when I didn't even know which ship is fighting against which ship. Now it's all colored and graphically presented and easy to understand.
The only little flaw with the anime, in my opinion, is the ED, which sounded like a Power Rangers song.